vfs_fruit: Add capability to advertise FULLSYNC

[github at samba.org]

New comment by andrewmiskell on Samba Github repository

https://github.com/samba-team/samba/pull/64#issuecomment-346244381
Comment:
@Henrik41 it's not a simple patch, you'll need to download the source and compile/install it yourself as the official release of 4.8 isn't available yet. you won't see it in a simple package form until then and even then, you may need to upgrade your version of Ubuntu if the samba 4.8 package isn't made available for that version of ubuntu.